Archives Of Health News Blog From Medicineworld.Org

January 14, 2008, 5:16 PM CT

Aggression as rewarding as sex, food and drugs

Bull fight

New research from Vanderbilt University shows for the first time that the brain processes aggression as a reward - much like sex, food and drugs - offering insights into our propensity to fight and our fascination with violent sports like boxing and football.

The research will be published online the week of Jan. 14 by the journal Psychopharmacology.

Aggression occurs among virtually all vertebrates and is necessary to get and keep important resources such as mates, territory and food, Craig Kennedy, professor of special education and pediatrics, said. We have observed that the reward pathway in the brain becomes engaged in response to an aggressive event and that dopamine is involved.

It is well known that dopamine is produced in response to rewarding stimuli such as food, sex and drugs of abuse, Maria Couppis, who conducted the study as her doctoral thesis at Vanderbilt, said. What we have now found is that it also serves as positive reinforcement for aggression.

For the experiments, a pair of mice - one male, one female - was kept in one cage and five intruder mice were kept in a separate cage. The female mouse was temporarily removed, and an intruder mouse was introduced in its place, triggering an aggressive response by the home male mouse. Aggressive behavior included tail rattle, an aggressive sideways stance, boxing and biting.........

Decision-making deficits in older adults

We often read or hear stories about elderly adults being conned out of their life savings, but are older individuals really more susceptible to fraud than younger adults? And, if so, how exactly does aging affect judgment and decision-making abilities?

Recent work led by University of Iowa neuroscientist Natalie Denburg, Ph.D., suggests that for a significant number of elderly adults, measurable neuropsychological deficits do seem to lead to poor decision-making and an increased vulnerability to fraud. The findings also suggest that these individuals may experience disproportionate aging of a brain region critical for decision-making.

"Our research suggests that elders who fall prey to fraudulent advertising are not simply gullible, depressed, lonely or less intelligent. Rather, it is truly more of a medical or neurological problem," said Denburg, who is an assistant professor of neurology in the UI Roy J. and Lucille A. Carver College of Medicine. "Our work sheds new light on this problem and perhaps may lead to a way to identify people who are at risk of being deceived".

Being able to identify how aging affects judgment and decision-making abilities could have broad societal implications. How to combat deceptive advertising targeted at older individuals -- some of whom appear to be especially vulnerable to fraud -- is one important area of concern. In addition, older age is a time when individuals often are faced with a number of critical life decisions, including health care and housing choices, investment of retirement income, and allocation of personal wealth.........

Fish oil: Helpful or harmful?

Fish oil supplements may help some cardiac patients while harming others, suggests a new review of evidence compiled by St. Michaels Hospital and University of Toronto researchers.

In a systematic review of trials where patients with implantable cardioverter defibrillators used fish oil supplements, Dr. David Jenkins and Dr. Paul Dorian found significant differences among the trials, indicating fish oil may be beneficial to some patients while having a negative impact on others.

Fish oils can have complex and varied effects on the heart, says Jenkins, a U of T Professor of Medicine who runs the Clinical Nutrition and Risk Factor Modification Centre at St. Michaels Hospital. These effects include blocking cardiac ion channels, reducing fibrosis in response to mechanical stress, decreasing blood coagulation, and possibly altering immune function.

There is evidence from multiple large-scale population (epidemiologic) studies and randomized controlled trials that intake of recommended amounts of DHA and EPA in the form of dietary fish or fish oil supplements can reduce the risk of death, heart attack and dangerous abnormal heart rhythms in people with known cardiovascular disease, as well as potentially slow hardening of the arteries and lower blood pressure slightly. But the evidence also shows high doses can have harmful effects, such as an increased risk of bleeding. Eventhough benefits are proposed for alpha-linolenic acid, scientific evidence is less compelling and beneficial effects may be less pronounced.........

Weight-loss Tips Differ In African-american

Magazines catering to African-Americans may be falling short in their efforts to educate readers about weight loss, a new University of Iowa study suggests.

African-American women's magazines are more likely to encourage fad diets and reliance on faith to lose weight, while mainstream women's magazines focus more on evidence-based diet strategies, as per the study by UI researcher Shelly Campo, published in a recent issue of the journal Health Communication.

"Three-quarters of African-American women are considered overweight or obese, in comparison to one-third of all U.S. women," said Campo, an assistant UI professor with appointments in community and behavioral health in the College of Public Health and communication studies in the College of Liberal Arts and Sciences. "African-American magazines tend to embrace a mission of advocacy for the African-American community, but if you're not covering evidence-based weight-loss strategies, you're not really helping your community".

Campo and co-author Teresa Mastin, an associate professor in the Department of Advertising, Public Relations, and Retailing at Michigan State University, analyzed 406 fitness and nutrition articles published between 1984 and 2004 in three major African-American women's magazines -- Ebony, Essence and Jet -- and three popular mainstream women's magazines -- Good Housekeeping, Better Homes and Gardens, and Ladies' Home Journal.........

Body weight influenced by thousands of genes

Reporting in the online journal BMC Genetics, scientists from the Monell Center have for the first time attempted to count the number of genes that contribute to obesity and body weight.

The findings suggest that over 6,000 genes about 25 percent of the genome help determine an individuals body weight.

Reports describing the discovery of a new obesity gene have become common in the scientific literature and also the popular press, notes Monell behavioral geneticist Michael G. Tordoff, PhD, an author on the study.

Our results suggest that each newly discovered gene is just one of the a number of thousands that influence body weight, so a quick fix to the obesity problem is unlikely.

To obtain an estimate of how a number of genes contribute to body weight, the Monell scientists surveyed the Jackson Laboratory Mouse Genome Database for information on body weights of knockout mouse strains.

Knockout mice have had a specific gene inactivated, or "knocked out. By studying how the knockout mice differ from normal mice, scientists obtain information about that genes function and how it might contribute to disease. Mice can provide valuable information on human disease because they share a number of genes with humans.

The knockout approach is so useful that the inventors of the technology were awarded the 2007 Nobel Prize in Medicine. Knockout mice are now standard tools in all mouse models of behavior and disease.........

Anyone can save a life

Anyone can save a life. Thats the message from physicians at the University of Pennsylvania School of Medicine.

Benjamin S. Abella, MD, MPhil, Clinical Research Director of Penns Center for Resuscitation Science and Assistant Professor of Emergency Medicine, says bystanders can play a critical role in saving lives by performing cardiopulmonary resuscitation during the 150,000 cardiac arrests that occur each year outside of hospitals in the United States. Abella served as lead author of a statement released recently by the American Heart Association in the journal Circulation that outlines the ways in which communities can encourage better bystander CPR.

Too often, even people whove been trained in cardiopulmonary resuscitation are afraid to perform it because they worry theyll harm the patient by not following the right steps. Others say theyre concerned about legal liability, despite Good Samaritan laws that protect bystanders who step in to help.

Studies show that only 15 to 30 percent of sudden cardiac arrest victims receive bystander CPR before emergency personnel arrive, Abella says. But chances for survival plummet as minutes tick by without any blood circulating through the body. Early bystander CPR, however, doubles to triples survival rates.........

Causes and consequences of childhood obesity?

The January 2008 special issue of The Annals, published by SAGE, explores the problem of obesity in the young, providing kids, their parents and caregivers a road map for a healthier lifestyle both for them and for future generations. From agreeing on the terminology to use, to possible public policy options, the articles in the special issue provide hope that this alarming crisis can be diffused, investigating such subjects as:

The environment of the developing child, including the home, school and neighborhood.

Parenting styles.

Food and beverage marketing in schools and in the media.

Intervention and prevention.

Clearly we need to help the 9 million children in this country who are overweight, and we need to do it now, writes Amy Jordan, Guest Editor, author, and director of the Media and the Developing Child sector of the Annenberg Public Policy Center at the University of Pennsylvania. The authors in this special issue provide a research agenda that, if implemented, will continue the interdisciplinary approach we have taken to understand the problem of childhood overweight and obesity and the collective effort we will need to solve it.........

Warning over severe weight loss caused by chewing gum

In this weeks BMJ, doctors warn of excess sorbitol intake, a widely used sweetener in sugar-free products such as chewing gum and sweets.

Sorbitol has laxative properties and is poorly absorbed by the small intestine.

Their advice follows the cases of two patients with chronic diarrhoea, abdominal pain and severe weight loss. Eventhough extensive investigations were carried out, final diagnosis was only established after detailed analysis of eating habits.

On questioning, both patients admitted consuming substantial amounts of sugar-free gum and sweets.

The first patient (a 21 year old woman) chewed large amounts of sugar-free gum, accounting for a total daily dose of 18-20g sorbitol (one stick of chewing gum contains about 1.25g sorbitol). The second patient (a 46 year old man) reported chewing 20 sticks of sugar-free gum and eating up to 200g of sweets each day, which together contained around 30g sorbitol.

After both patients started a sorbitol free diet, diarrhoea subsided, normal bowel movements resumed and weight gain was achieved.

As possible side effects are commonly found only within the small print on foods containing sorbitol, consumers may be unaware of its laxative effects and fail to recognise a link with their gastrointestinal problems, write the authors.........

"Pay-for-performance" Improves Patient Care

A new study examines whether patients seeing physicians participating in a "pay-for-performance" incentive program receive better care than those who saw non-participating physicians. The health plan that was examined reimburses physicians based on the quality of care they provide.

This study finds a strong connection between quality of patient care and doctor participation in a quality-based incentive program. This association grew even stronger over time, with patients who saw program-member doctors exclusively during the trial period experiencing significantly better quality of care than those that did not.

Looking at eleven evidence-based quality indicators, such as screening for many different cancers, the study provides a comparison between traditional and quality-based payment assessments over a six-year period.

"The concept of reimbursing providers based-at least in part-on the quality of care is not only a novel approach that is gaining popularity within the health care sector, but an innovation that may have the potential to improve the quality of care," says Dr. Antonio P. Legorreta, lead author of the study.........

Eat less or exercise more?

Overweight people who lose a moderate amount of weight get an immediate benefit in the form of better heart health, as per a research studyconducted at Washington University School of Medicine in St. Louis. And the heart improvements happen whether that weight is shed by eating less or exercising more.

"If individuals want to do something that's good for their heart, then my message to them is lose weight by the method they find most tolerable," says the study's senior author Sndor J. Kovcs, Ph.D, M.D., director of the Cardiovascular Biophysics Laboratory and professor of medicine. "They're virtually guaranteed that it will have a salutary effect on their cardiovascular system".

Studying a group of healthy, overweight but not obese, middle-aged men and women, the scientists observed that a yearlong regimen of either calorie restriction or exercise increase had positive effects on heart function. Their analysis revealed that heart function was restored to a more youthful state so that during the heart's filling phase (called diastole) it took less time for participants' hearts to relax and fill with blood. The findings will appear in an upcoming issue of the American Journal of Physiology and are now available online.

"As we get older, our tissues become more fibrotic as collagen fibers accumulate," says co-author of study John O. Holloszy, M.D., professor of medicine in the Division of Geriatrics and Nutritional Science. "So the arteries and heart muscle stiffen, and the heart doesn't relax as well after contracting. Similar studies that we've conducted with members of the Caloric Restriction with Optimal Nutrition Society (CRONies) show they have heart function resembling much younger people." CRONies voluntarily consume about 25 percent fewer calories than the average American while still maintaining good nutrition.........

Did you know?Studies in monkeys and women suggest that unlike traditional estrogen therapy, a diet high in the natural plant estrogens found in soy does not increase the risk of uterine cancer in postmenopausal women, according to Mark Cline, D.V.M., Ph.D., an associate professor of comparative medicine at Wake Forest University Baptist Medical Center.